From patchwork Tue May 22 16:01:03 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chandan Rajendra X-Patchwork-Id: 10419037 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 2D9C26053B for ; Tue, 22 May 2018 16:00:20 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1885628FEF for ; Tue, 22 May 2018 16:00:20 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0606D29027; Tue, 22 May 2018 16:00:20 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7E1B328FD6 for ; Tue, 22 May 2018 16:00:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751579AbeEVQAH (ORCPT ); Tue, 22 May 2018 12:00:07 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:20718 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751503AbeEVQAE (ORCPT ); Tue, 22 May 2018 12:00:04 -0400 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w4MFxJHI137716 for ; Tue, 22 May 2018 12:00:03 -0400 Received: from e36.co.us.ibm.com (e36.co.us.ibm.com [32.97.110.154]) by mx0a-001b2d01.pphosted.com with ESMTP id 2j4n95c3kk-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 22 May 2018 12:00:03 -0400 Received: from localhost by e36.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Tue, 22 May 2018 10:00:00 -0600 Received: from b03ledav003.gho.boulder.ibm.com (b03ledav003.gho.boulder.ibm.com [9.17.130.234]) by b03cxnp07028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w4MFxxtb14352760; Tue, 22 May 2018 08:59:59 -0700 Received: from b03ledav003.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B44336A043; Tue, 22 May 2018 09:59:59 -0600 (MDT) Received: from localhost.localdomain.com (unknown [9.85.71.81]) by b03ledav003.gho.boulder.ibm.com (Postfix) with ESMTP id 8A7D36A03C; Tue, 22 May 2018 09:59:57 -0600 (MDT) From: Chandan Rajendra To: linux-fscrypt@vger.kernel.org Cc: Chandan Rajendra , ebiggers3@gmail.com, tytso@mit.edu, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [RFC PATCH V3 05/12] ext4: Decrypt all boundary blocks when doing buffered write Date: Tue, 22 May 2018 21:31:03 +0530 X-Mailer: git-send-email 2.9.5 In-Reply-To: <20180522160110.1161-1-chandan@linux.vnet.ibm.com> References: <20180522160110.1161-1-chandan@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18052216-0020-0000-0000-00000DFC39F4 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009066; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000261; SDB=6.01036072; UDB=6.00529991; IPR=6.00815201; MB=3.00021242; MTD=3.00000008; XFM=3.00000015; UTC=2018-05-22 16:00:02 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18052216-0021-0000-0000-000061807124 Message-Id: <20180522160110.1161-6-chandan@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2018-05-22_05:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1805220177 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP With block size < page size, ext4_block_write_begin() can have up to two blocks to decrypt. Hence this commit invokes fscrypt_decrypt_page() for each of those blocks. Signed-off-by: Chandan Rajendra --- fs/ext4/inode.c | 37 +++++++++++++++++++++++++------------ 1 file changed, 25 insertions(+), 12 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 5df4c7e..736d209b 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1158,12 +1158,14 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len, unsigned to = from + len; struct inode *inode = page->mapping->host; unsigned block_start, block_end; - sector_t block; + sector_t block, page_blk_nr; int err = 0; unsigned blocksize = inode->i_sb->s_blocksize; unsigned bbits; - struct buffer_head *bh, *head, *wait[2], **wait_bh = wait; + struct buffer_head *bh, *head, *wait[2]; + int nr_wait = 0; bool decrypt = false; + int i; BUG_ON(!PageLocked(page)); BUG_ON(from > PAGE_SIZE); @@ -1216,7 +1218,7 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len, !buffer_unwritten(bh) && (block_start < from || block_end > to)) { ll_rw_block(REQ_OP_READ, 0, 1, &bh); - *wait_bh++ = bh; + wait[nr_wait++] = bh; decrypt = ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode); } @@ -1224,18 +1226,29 @@ static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len, /* * If we issued read requests, let them complete. */ - while (wait_bh > wait) { - wait_on_buffer(*--wait_bh); - if (!buffer_uptodate(*wait_bh)) + for (i = 0; i < nr_wait; i++) { + wait_on_buffer(wait[i]); + if (!buffer_uptodate(wait[i])) err = -EIO; } - if (unlikely(err)) + if (unlikely(err)) { page_zero_new_buffers(page, from, to); - else if (decrypt) { - err = fscrypt_decrypt_page(page->mapping->host, page, - PAGE_SIZE, 0, page->index); - if (err) - clear_buffer_uptodate(*wait_bh); + } else if (decrypt) { + page_blk_nr = (sector_t)page->index << (PAGE_SHIFT - bbits); + + for (i = 0; i < nr_wait; i++) { + int err2; + + block = page_blk_nr + (bh_offset(wait[i]) >> bbits); + err2 = fscrypt_decrypt_page(page->mapping->host, page, + wait[i]->b_size, + bh_offset(wait[i]), + block); + if (err2) { + clear_buffer_uptodate(wait[i]); + err = err2; + } + } } return err;